Rowan Williams failed as archbishop of Canterbury, because the job description makes success impossible. But the announcement of his resignation makes clear that he failed at one particular impossible task he set himself: to hold together the Anglican communion. That gathering – now more of a dispersal – of 38 churches worldwide continued the schism between liberals and conservatives which has been under way since the 1990s. Both here and abroad, Dr Williams made enough sacrifices for unity to alienate his liberal supporters without satisfying his conservative enemies. But this is what he felt was his duty as archbishop, and in the patient and humble way he followed this thankless path, jeered at from left and right, he offered an example that not only Christians found attractive.

Personal charm

It would be too simple and glib to write him off as a good man but a bad archbishop. His personal humility was countered by a certain intellectual aloofness: he was on occasion astonishingly naive to suppose that his speeches would be read, and the soundbites not heard. He took a long time to realise that he had enemies who really hated him and really wanted to destroy the Church of England. Sometimes he seemed to think that the effects of his personal charm and force alone would be enough to carry arguments.

In his attempts to make a place in the Church of England both for women bishops and for the men who refuse to recognise them as bishops, he failed to convince either side of his passionate belief that God wanted them to keep on talking and arguing.

This means that an important area of his mandate now has to be classed as unfinished business. Yet these have to be set against all of the things that might have gone wrong and did not. Here, too, it was his personality as much as his policies which triumphed. The threat of large-scale defections by the opponents of women priests receded into farce after the pope, perhaps misled by the industrious machinations of an Anglo-Catholic clique within the Church of England, announced the formation of a special body to which such priests and their congregations could convert as a group. Hardly any of them did.

Nor was Dr Williams by instinct a centraliser, or someone who believed that the right bureaucratic setup could rescue the church. He put his trust, perhaps too often, in the Holy Spirit. Some thought his style of management was vaguely benevolent, but it did no harm and in his time the rate of decline in church attendance slowed to almost nothing. This was all part of his success in the management of creeping disestablishment. That is not a formal process, but a shapeless and informal one, through which the Church of England comes to seem more and more peripheral to the real concerns of the country. Dr Williams did a great deal to slow or reverse this process. His intellectual force, and his tremendous seriousness, made it seem that the church had a huge amount to offer a country that was trying to understand itself. His writings might sometimes seem exercises in academic display, but it was obvious, when he spoke, that he always cared. He could talk to murderers, to politicians, and even journalists, without condescension. He believed in discussion rather than decrees. He sounded sharp-edged and urgent when speaking about real problems. The idea that devout Christians must be stupid, ignorant or bigoted could not be taken seriously by anyone who listened to the archbishop. Amid the rhetoric of the "war on terror", he stood for humanity, moderation and sanity. His opposition to the war in Iraq, in particular, was measured but clear.

Speaking for the poor

This is a hard act to follow. None of the possible candidates have Dr Williams' stature as a public intellectual. No one can hope to unite the factions of the Church of England, still less the Anglican communion. What the next incumbent must do is make them realise that they have more in common than all that divides them. He will also need to talk to the media and to be heard through it. If he can manage that, then he stands a better chance of cutting through the cynicism which is out there among those to whom the church is irrelevant.

However, one of Dr Williams' sources of authority is open to all of them. The churches generally, and the Church of England in particular, are the only middle-class organisations which reach from the bottom of society to the top. Too often they have preached down to the poor but sometimes they have lifted up the voices of the wretched. At his best, Dr Williams could speak simply for all that common humanity. His successor will have to do so too.